Thanks for everyone's help. Anabel, I'll have a look at the thread. While i've got a thread going, I'll also ask another bit of advice if that's ok....
Grey Boy is a grey TB gelding, and we used to compete over 80cm+ show jumping, but while he was at an agistment centre, we were jumping their cross-country course and the jump was rotten wood and he knocked it and his hoof went right though the jump, and although he came out without a scratch, his confidence is way down, and he now refuses even tiny jumps 70% of jumps. The ones he does jump, he either jumps it only one direction and refuses the other direction, or only jumps them sometimes.
Help with this problem too?
I'd love to jump him again as he was very, very good.
The half-halt is also used as a "hey poneh, I am gonna ask you to do something in a second, is yew awake?".